Kimchi is a collective name of fermented vegetable foods representing Korea, which are prepared by salting various vegetables, blending with various seasonings and naturally aging. Especially, representative Kimchi is Gimjang () Kimchi, a main ingredient of which is Korean cabbage, i.e., Brassica campestris L. Gimjang Kimchi is prepared by salting Korean cabbage and radish harvested at late autumn to early winter, blending them with sub-ingredients such as garlic, ginger, green onion and so on and burying them underground and is served as winter food (Cheigh and Park, Biochemical, microbiological and nutritional aspects of Kimchi, Crit. Rev. FoodSci. Nutr. Vol. 34, 1981, pages 102-127). Like this, Gimjang Kimchi is categorized as cold fermentation preserves and is manufactured by keeping vegetables at low temperature during winter season when vegetables are not produced, through salting and fermentation methods. Gimjang Kimchi is served as sources of carbon, amino acid and vitamins and provides a rich fermentation flavor formed from processes of fermentation and aging with unique lactic acid bacteria in raw materials.
Recently, however, raw materials such as Korean cabbages can be produced and stored throughout a year owing to bread improvement and cultivation development and, therefore, Korean cabbage Kimchi can be manufactured even though it is not Gimjang season (i.e., winter). Further, the spread of refrigerator and Kimchi refrigerator have enables cold fermentation preservation as if it were winter. As a result, recent Kimchi is no more the same with the traditional Korean cabbage Gimjang Kimchi.
Basically, the quality of Kimchi significantly changes depending on that of various raw materials such as Korean cabbage which is recently forwarded throughout a year. The quality change of Kimchi has become an obstacle to providing products having constant quality with customers, especially in a position of business companies commercializing Kimchi. Especially, Kimchi manufactured in summer (June˜August) has problems like low quality of raw materials and deterioration of fermentation-aging flavor even though the Kimchi would be manufactured by the same fermentation and aging methods as in winter. It is well known in the art that a wide variation in quality depending on season has brought about various claims of quality dissatisfaction by customers.
Prior arts for solving the problems have tried to control Kimchi quality by adding various microorganisms, mainly lactic acid bacteria, as a starter (Korean Patent Nos. 10-0536108, 10-0181009, 10-0330674 and so on). The prior arts, however, applied starters merely for improving quality or confirmed that there is a difference of general taste quality in sensory test, regardless of season; they did not investigate causes of quality change during a year. Accordingly, there is no prior art that focuses on the quality improvement of summer Kimchi, analyzes the causes of quality deterioration and solves the problems.
Meanwhile, Kimchi lactic acid bacteria such as Leuconostoc Kimchii, Leuconostoc citreum, Leuconostoc mensenteroides, Leuconostoc gasicomitatum, Leuconostoc lactis, Lactobacillus plantarum and Lactobacillus sakei have been used individually or in combination in manufacturing various fermented foods.
Among them, Leuconostoc citreum bacteria is concerned in Kimchi aging and is known as its ability to produce polymer mucilages, dextran, with sugar (Korean Patent No. 10-0718344) and as being effective for treatment and prevention of atopic dermatitis (Korean Patent Application No. 10-2005-0041572). Further, Korean Patent No. 10-0814665 discloses Leuconostoc citreum S5 bacteria producing dextran and a method of producing fermented products comprising the dextran by using the bacteria and Korean Patent No. 10-080053 discloses Leuconostoc citreum producing mannitol and a method of producing mannitol using the bacteria.